1. Field of the Invention
With reference to the classification of art as established by the United States Patent Trademark Office the present invention is believed to be found in the general Class entitled, "Advancing Material of Indeterminate Length" (Class 226) and in the subclass thereunder entitled, "static guide" (subclass 196) and in the general Class entitled, "Photograph" (Class 354) and the subclass entitled, "fluid-treating apparatus -- with film immersed and removed" (subclass 319).
2. Description of the Prior Art Attempts
The developing of photographic film, both positive and negative, is an old and complex art. The improvements in the speed and color of films have made the close control of bath, speed and contact with the emulsion more critical with each advance in the film art. Many of the present films have soft, easily scratched emulsions particularly when immersed in developing solutions. Attemps to provide high speed, automatically and closely controlled roller transporting devices for film are many. Usually in addition to a spaced set of rollers there is provided outer curved guide members. Such a showing is found in U.S. Pat. No. 3,785,543 to LEE as issued on Jan. 15th, 1974. The prior art also discloses the use of belts and curved guides to insure the U-turn transporting of film through processing tanks.
In the present invention there is provided rollers which are offset from one another and are spaced so that a serpentine path for transporting the film is provided. The film to be transported, whether a positive or negative film, is contemplated to have enough residual stiffness in its base structure so that when bent from a normal flat plane the bent film will engage the periphery of the rollers sufficiently for the turning rollers to move the film forward.